Messages in this thread | | | Date | Wed, 5 Aug 2020 07:08:08 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v2] x86/cpu: Use SERIALIZE in sync_core() when available |
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On Tue, Aug 04, 2020 at 09:58:25PM -0700, hpa@zytor.com wrote: > Because why use an alternative to jump over one instruction? > > I personally would prefer to have the IRET put out of line
Can't yet - SERIALIZE CPUs are a minority at the moment.
> and have the call/jmp replaced by SERIALIZE inline.
Well, we could do:
alternative_io("... IRET bunch", __ASM_SERIALIZE, X86_FEATURE_SERIALIZE, ...);
and avoid all kinds of jumping. Alternatives get padded so there would be a couple of NOPs following when SERIALIZE gets patched in but it shouldn't be a problem. I guess one needs to look at what gcc generates...
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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